Photographic printer



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PHOTOGRAPHIC PRINTER Original Filed Jan. 30, 1959 2 Sheets-Sheet 2xiv/288 J 3 L; Y 304 l 307 il@ f l292 il 302\ D l 36m j J j s oB J)P3026 l l U,33oa14?2 530s "335B 335s 3376 35 34ml o 5 o 333e 3346 3MB334B sala sos D Ylr R-u "4 R R R R 9 5 7 7 O R R R s 9 M 3W 6 2 3 8 3RIOS-3| 7 67 2 3 7443 3 33 \|/\lf 333.5 8 R 3 o 7 A 5 1 4. l 3 9 3 l I|I l 7 2 3 R G 3 R 2 u u 3 v Q l R w n m 4 3 m n 4 4 3 3 3 3 UnitedStates Patent O 3,220,304 PHOTOGRAPHIC PRINTER Roy A. Clapp, CoonRapids, Minn., assignor to Pako Corporation, Minneapolis, Minn., acorporation of Delaware Original application Jan. 30, 1959, Ser. No.790,226, now Patent No. 3,100,419, dated Aug. 13, 1963. Divided and thisapplication Sept. 20, 1962, Ser. No. 225,099 8 Claims. (Cl. 88-24) Thisapplication for patent relates to photographic printers and is adivision of my copending application for patent for PhotographicPrinter, Serial No. 790,226, led January 30, 1959, now U.S. Patent No.3,100,419, issued Aug. 13, 1963.

The invention further relates to the printing of photographic materialshaving two or more emulsions by the use of light having components towhich the emulsions are sensitive and in the printing of which the lightof any component is cut off when suflicient exposure to such componenthas been procured.

An object of the invention resides in providing a photographic printerin which the desired color balance of the print may be procured withoutaltering the density of the print.

Another object of the invention resides in providing for each color,color modifying means and cut oil means operated thereby, and in furtherproviding interlocking means between the modifying means operable uponincreasing the length of exposure by one light component to decrease thelength of exposure by certain of the other components.

An object of the invention resides in providing adjustable emulsioncontrols for varying the exposure in accordance with emulsioncharacteristics of the paper without disturbing the basic color balance.

A still further object of the invention resides in providing electricalcircuits for procuring the desired results.

An object of the invention resides in providing a control circuit foreach color and cut olf means for each y color controlled thereby and inproviding color modifying n the length of exposure of one emulsion,variation of certain of said other elements in a manner to cause adecrease in the length of exposure of the emulsions for thecorresponding other colors.

Another object resides in utilizing trigger circuits for operating saidcut off means and including electronic valves and in utilizing saidmodifying circuits for controlling the operation of said valves.

A still further object of the invention resides in utilizing in saidtrigger circuits electronic valves adapted to become operative upon theapplication of a predetermined voltage thereto and in utilizing in saidmodifying circuits variable resistors for controlling the voltagesapplied to said valves.

An object of the invention resides in gang operating certain of saidresistors to produce upon increase of the resistance of the resistor forone color in each of said modifying circuit the decrease of theresistance of the resistors for certain of the other colors in the othermoditying circuits.

Other objects of the invention reside in the novel construction andarrangement of parts and in the details of construction hereinafterillustrated and/or described.

In the drawings:

FIG. l is a wiring diagram of a portion of the electrical system of aphotographic printer illustrating an embodiment of the invention.

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FIG. 2 is a wiring diagram of the remainder of the elec trical system ofthe photographic printer.

The invention disclosed in this application for patent is for use inprinting color material and is particularly applicable for use withphotographic printing paper having three emulsions sensitive to red,green and blue light. To simplify the description of the invention andto prevent needless repetition, the parts and components pertaining tothe printing of the red emulsion will be described and referencenumerals with the letter R added. The parts and components correspondingthereto and pertaining to the green and blue emulsions will not be againdescribed but will be given the same reference numerals as those appliedto the red parts and components and to which will be appropriately addedthe letters G and B. The same reference numerals used in the parent casewill also be used in this case to indicate the like parts. While theentire electrical system of the invention has been shown in thedrawings, only so much of the same as directly pertains to the presentinvention will be described, reference to the parent case being had forthe balance of the circuits and the structural parts of the printer.

The photographic printing apparatus in which the instant invention isemployed is mounted on a table which supports the various sections ofthe same. Extending upwardly from said table at one end thereof is acolumn which supports a paper section and an optical section. These twosections are movable in an up and down direction to focus the image onthe paper. Mounted on the table at the intermediate portion of the sameis an illuminating section by means of which light may be passed througha negative carried by a negative holder disposed at the upper surface ofthe table. A light valuating section is used in conjunction with theoptical section to sample the light and to alter the exposure time ofthe light component of the printing light in accordance with therequirement for the particular negative being printed. The sample lightis directed to a distributor which distributes samples of the primarycolors to three diiferent channels. In these channels, timers for thethree colors are employed, which control the photographic exposure ofthe respective color emulsions on the photographic material. Cut offmeans in the form of iilters are used in conjunction with the lightsource which is operated by the timers and which alters the color of theprinting light to compensate for the color deficiencies of thenegatives.

The electrical section of the apparatus of which the instant inventionforms a part receives signal pulses from the distributor and feeds it tothree exposure compensating circuits LR, LG Aand LB. The exposurecompensating circuits LR, LG and LB are used for compensating forgrossly overexposed and underexposed negatives. The energy from thesecircuits is fed to three timers IR, IG and IB which control the durationof the exposure for each color and which include interpolating circuitsMR, MG and MB and trigger circuits QR, QG, and QB. The interpolatingcircuits MR, MG, and MB are employed for producing continuous operationswith a pulse type signal. The trigger circuits are employed to operatethe cut Off means for terminating the printing of each emulsion of thephotographic material. The operation of the cut off means is furthercontrolled by manually operated density modifying means N includingdensitymodifyin'g circuits NR, NG and NB, light compensating means Pincluding light compensating circuits PR, PG and PB. The lightcompensating circuits PR, PG yand PB are used for selectively printingprints from negatives exposed either by flash illumination or outdoorillumination, and by the color modifying system O comprising colormodifying means or circuits OR, OG, and OB and which forms the subjectmatter of the instant invention. All these E 3 circuits and the variousfunctions of the machine are controlled by the programming section K.The programming section of the invention is illustrated in FIG. 2 whilethe other electric-al sections of the invention are illustrated in FIG.1.

The photographic printing apparatus embodying the instant invention isillustrated in FIG. 1 and comprises the three color modifying circuitsOR, OG, and OB. Power for operating these circuits is derived from a thethree gangs of switches are moved from one position to another toincrease or decrease the resistance in one of the color circuits, theresistance in each of the other color circuits is decreased or increasedby an amount equal to one-half of the increase or decrease in thedenoted circuit, thus maintaining the entire resistance in the threecircuits the same.

Applicant has found by actual use that the following types and values ofcomponents give satisfactory results:

KXXXXXXXX te te te s: te te te te NXXSXXXXXXXKXXXXX power line 404connected to a source of direct current of about 250 volts, This linecomprises a conductor 405 which is connectedto the positive side of thesource of power and a conductor 406 which is connected to the negativeside and which is grounded. The circuits OR, OG and OB includepotentiometers 261K, 261G and 261B. One end of each of thesepotentiometers is connected to a conductor 329 which in turn isconnected to the positive side 405 of the line 404. The other ends ofthese potentiometers are connected through conductor 264R, 2'64G and264B to resistors 265R, 265G and 265B. These resistors are all groundedthrough a conductor 266. These potentiometers are calibrated in terms ofemulsion factors and are `adjusted to correspond to the emulsion factorof the particular paper being used. The circuits OR, OG and OB utilizethree single pole three-position switches for each color designated bythe-numerals 267R, 267G, 267B, 268R, 268G, 268B, 269R, 269G and 269B.The. switches 267R, 268G and 269B are ganged and move in unison.Similarly, the switches 267B, 268R and 269G are ganged and also theswitches 267G, 268B -and 269K are ganged and likewise move in unison.The switches 267R, 268R and 269R have connected to the fixed contacts ofthe same resistors 271R, 272R, 273R, 274K, 275R and 276R. Similarresistors are connected to the other switches. The resistor 271R isconnected through a conductor 277R to the movable Contact of thepotentiometer 261R. The movable contact of the switch 267K is connectedby a conductor 278R to the movable contact of switch 268k. The resistor274K is connected by a conductor 279R to the movable contact of theswitch 269K. The resistor 276R is connected by a conductor 281R to themovable contact of the switch 253R forming part of thelight'compensating circuit PB. When any of The operation of theinvention is as follows: The color modifying circuits OR, OG and OBthrough the power supply 404, furnish three voltages which are impressedon the three light compensating circuits PR, PG and PB. These circuitscontain switches 2S3R, 253C?, and 253B, and resistors 254R, 254G, 254B,255R, 255G and 255B which vary the voltages impressed on the circuitsPR, PG and PB and provide terminal voltages which are proper to give thecorrect exposure for either daylight or artificial illumination in thetaking of the picture. The resulting voltages are impressed upon thecathodes 247R, 247G and 247B of the trigger tubes 254R, 254G and 254B oftrigger circuits QR, QG and QB and provide bias voltages for the same,thus controlling to a certain extent the amount of time elapsing beforeeach of said trigger tubes fires. The timers of the printer activated bythe light valuating section furnish grid voltages for the buffercircuits SR, SG and SB and which in turn provide grid current for thegrids 247R, 247G and 247B of the trigger tubes 245R, 24SG and 245B thusfurther controlling the amount `of time elapsing before each triggertube tires. As the tubes iire the cut off means for each color isoperated and the proper exposure for each emulsion results.

The advantages of the invention are manifest. The color balance of theprinted material may be manually varied to suit the requirements and thedensity of the print automatically maintained constant. The desiredresult is procured by the use of ordinary resistors and ganged electricswitches which are arranged so that when the resistance for one color isincreased the resistances for the other colors are reduced and visaversa. Once the proper resistances have been selected the device needsno `further attention. With the invention, each color maybe separatelyvaried and similarly any two may be varied,`

Changes in the specific form of the invention, as herein described, maybe made within the scope of what is claimed without departing from theSpirit of the invention.

Having described the invention, what is claimed as new and desired to beprotected by Letters Patent is:

1. In a photographic printer for color printing comprising a holder foran image bearing support, means for supporting multiple sensitizedmaterial having three emulsions in printing relation to said support,illuminating means containing three light components of different colorsfor illumina-ting said support, individual cut oftr means forindividually cutting olf each of said light components, individual colormodifying means controlling the operation of each of said cut off means,and interlocking means between said modifying means whereby increasingthe length of exposure by one light component a certain amount decreasesthe length of exposure of each of the other two light components by anamount equal to one half of the amount of increase of the length ofexposure of the first referred to light component.

2. In a photographic printer for color printing having three separatetrigger -circuits to control the exposure of the sever-al emulsions ofsensitized printing material having three emulsions, said circuits eachincluding an electronic valve normally inoperative and functioning tocontrol the exposure of one of the emulsions of the sensitized materialwhen the voltage applied thereto reaches a predetermined value, thecombination of three individual color modifying circuits one for eachtrigger circuit, each adapted to apply a voltage to one of the elementsof the valve of one of said trigger circuits, a principal variableresistor in each of said modifying circuits for one of said emulsionsand two auxiliary variable resistors in each of said color modifyingcircuits for the same emulsions and of one h-alf the value of theprincipal resistor said resistors being connected in series and varyingthe voltage applied to said valves and three dependent gang operatingmeans each simultaneously operating one principal variable resistor forone emulsion and an auxiliary resistor for each of the other emulsionsin a manner to cause upon increase of the resistance of the principalresistor in one modifying circuit the decrease of the resistance of theauxiliary resistors in the other two modifying circuits for the otheremulsions.

3. In a photographic printer for color printing having separate triggercircuits to control the exposure of the several emulsions of thesensitized printing material, said circuits including gas lledelectronic valves with plates, grids and cathodes, the combination ofcolor modifying circuits, one for each trigger circuit connected to thecathodes of said valves and to a source of voltage, a principal variableresistor in each of said modifying circuits for one of said emulsionsand auxiliary variable resistors in each of said color modifyingcircuits for the same emulsions and of lesser value than the principalresistor said resistors being connected in series and independent gangoperating means for simultaneously operating one principal variableresistor for one emulsion and a variable resistor for certain of theother emulsions in a manner to cause upon increase of the resistance ofthe principal resistor in one modifying circuit the decrease of theresistance of the auxiliary resistors in the modifying circuits for saidother certain emulsions.

4. In a photographic printer for color printing having separate triggercircuits to control the exposure of the several emulsions of thesensitized printing material, said circuits including gas filledelectronic valves with plates, grids and cathodes, the combination ofcolor modifying circuits, one for each trigger circuit connected to thecathodes of said valves and to a source of voltage, a variable biascontrol voltage divider in each of said circuits normally set to producethe proper color balance for a particular kind of multiple sensitizedphotographic material, an emulsion -factor variable voltage divider ineach of 6. said color modifying circuits controlling the voltage appliedto said first named voltage dividers and calibrated in terms of thecorresponding emulsion factor of the multiple sensitized photographicmaterial.

5. In a photographic printer for color printing having separate triggercircuits to control the exposure of the several emulsions of thesensitized printing material, said circuits including gas filledelectronic valves with plates, grids and cathodes, the combination ofcolor modifying circuits, one for each trigger circuit connected to thecathodes of said valves and to a source of voltage, a variable biascontrol voltage divider in each of said circuits normally set to producethe proper color balance for a particular kind of multiple sensitizedphotographic material, an emulsion factor variable voltage divider ineach of said color modifying circuits controlling the voltage applied tosaid first named voltage dividers and calibrated in terms of thecorresponding emulsion factor of the multiple sensitized photographicmaterial, a number of variable resistors connected in series in eachcolor modifying circuit and disposed between the voltage dividerstherein, and manually controlled resistance varying devices connected toand varying a resistor in each of said color modifying circuits tocompensate for color unbalance.

6. In a photographic printer for color printing having separate triggercircuits to control the exposure of the several emulsions of thesensitized printing material, said circuits including gas filledelectronic valves with plates, grids and cathodes, the combination ofcolor modifying circuits, one for each trigger circuit connected to thecathodes of said valves and to a source of voltage, a variable biascontrol voltage divider in each of said circuits normally set to producethe proper color balance for a particular kind of multiple sensitizedphotographic material, an emulsion factor Variable voltage divider ineach of said color modifying circuit controlling the voltage applied tosaid first named voltage dividers and calibrated in terms of thecorresponding emulsion yfactor of the multiple sensitized photographicmaterial, a number of variable resistors connected in series in eachcolor modifying circuit and disposed between the voltage dividerstherein, manually controlled resistance varying devices connected to andvarying the resistance of a resistor in each of said color modifyingcircuits to compensate for color unbalance, and interlocking meansbetween a resistance varying device of each of said color controlcircuits causing simultaneous variation of the resistance of saidresistor to produce increase of resistance of one of said resistors anddecrease the resistance of the other of said resistors.

7. In a photographic printer for color printing having separate triggercircuits to control the exposure of the several emulsions of thesensitized printing material, said circuits including gas filledelectronic valves with plates, grids and cathodes, the combination ofcolor modifying circuits, one for each trigger circuit connected to thecathodes of said valves and to a source of voltage, a variable biascontrol voltage divider in each of said circuits normally set to producethe proper color balance for a particular kind of multiple sensitizedphotographic material, an emulsion factor variable voltage divider ineach of said color modifying circuits controlling the voltage applied tosaid rst named voltage dividers and calibrated in terms of thecorresponding emulsion factor of the multiple sensitized photographicmaterial, a number of variable resistors connected in series in eachcolor modifying circuit and disposed between the voltageI dividerstherein, manually controlled resistance in each of said color modifyingcircuits to compensate for color unbalance, and interlocking meansbetween a resistance. varying device of each of said color controlcircuits causing simultaneous variation of the resistance of saidresistor to produce increase of resistance of one of said resistors anddecrease the resistance of the other of said resistors, said resistorsand resistance varying devices being constructed so that the sum of theresistance in all of the color modifying circuits remains constant uponvariation of said reSis-tance varying devices.

8. In a photographie printer for color printing having three separatetrigger circuits to control the exposure of the several emulsions ofsensitized printing material having three emulsions, said circuits eachincluding an electronic valve normally inoperative and functioning tocontrol the exposure of one of the emulsions of the sensitized materialwhen the voltage applied thereto reaches a predetermined value, thecombination of three individual color modifying circuits one for eachtrigger circuit, each adapted to apply a voltage to one of the elementsof the valve of one of said trigger circuits, a principal variableresistor in each of said modifying circuits for one of said emulsionsand two auxiliary variable resistors in each of said color modifyingcircuits for the same emulsions and of one half the value of theprincipal resistor, said resistors being all similar in construction andeach comprising an elongated resistive element having a connected endand an open end and each having a contactor contacting with and movablealong said resistive element from one end to the other, means forcausing simultaneous movement of said contactors in the same direction,said means when bringing the contactor of the principal resistor intocontact with the connected end of the resistance element of theprincipal resistor also bringing the other two contactors in contactwith the free ends of the resistive elements of the auxiliary resistors.

References Cited by the Examiner UNITED STATES PATENTS 2,43 8,303 3/1948 Simmon. 2,518,947 8/ 1950 Simmon 88-24 2,518,948 8/1950 Simmon.

2,921,498 1/ 1960 Simmon et al. 88-24 NORTON ANSI-IER, Primary Examiner.

EMIL G. ANDERSON, Examiner.

1. IN A PHOTOGRAPHIC PRINTER FOR COLOR PRINTING COMPRISING A HOLDER FORAN IMAGE BEARING SUPPORT, MEANS FOR SUPPORTIN MULTIPLE SENSITIZEDMATERIAL HAVIN THREE EMULSIONS IN PRINTING RELATION TO SAID SUPPORT,ILLUMINATING MEANS CONTAINING THREE LIGHT COMPONENTS OF DIFFERENT COLORSFOR ILLUMINATIN SAID SUPPORT, INDIVIDUAL CUT OFF MEANS FOR INDIVIDUALLYCUTTIN OFF EACH OF SAID LIGHT COMPONENTS, INDIVIDUAL COLOR MODIFYINGMEANS CONTROLLIN THE OPERATION OF EACH OF SAID CUT OFF MEANS, ANDINTERLOCKING MEANS BETWEEN SAID MODIFYIN MEANS WHEREBY INCREASIN THELENGTH OF EXPOSURE BY ONE LIGHT COMPONENT A CERTAIN AMOUNT DECREASES THELENGTH OF EXPOSURE OF EACH OF THE OTHER TWO LIGHT COMPONENTS BY ANAMOUNT EQUAL TO ONE HALF OF THE AMOUNT OF INCREASE OF THE LENGTH OFEXPOSURE OF THE FIRST REFERRED TO LIGHT COMPONENT.